Publications by authors named "Heather McAllister"

In recent years, the need to accelerate drug discovery processes in the pharmaceutical industry has revived the interest of implementing automated workflows, allowing the simultaneous processing of multiple samples on global processes that are referred as High-Throughput Purification (HTP). In this work, SAPIO Laboratory Information Management System (SAPIO LIMS) has been customized at the HTP laboratories of Janssen R&D to accommodate the needs of global purification groups on several automated HTP workflows, integrating Analytical Studio™ data processing tool on multiple steps. Herein we describe the workflow details from crude analysis via RP-LC-MS or SFC-MS systems to sample redissolution and delivery to Compound Logistics (CL) in tubes ready for assay plate preparation.

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[4-(4-Methyl-2-(4-(trifluoromethyl)phenyl)thiazole-5-yl)pyrimidine-2-amine] (JNJ-2482272), under investigation as an anti-inflammatory agent, was orally administered to rats once daily at 60 mg/kg for 6 consecutive days. Despite high plasma exposure after single administration (C of 7.1 M), JNJ-2482272 had plasma concentrations beneath the lower limit of quantification (3 ng/ml) after 6 consecutive days of dosing.

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Excitatory amino acid transporters (EAATs) represent a protein family that is an emerging drug target with great therapeutic potential for managing central nervous system disorders characterized by dysregulation of glutamatergic neurotransmission. As such, it is of significant interest to discover selective modulators of EAAT2 function. Here, we applied computational methods to identify specific EAAT2 inhibitors.

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At the onset of a drug discovery program, the goal is to identify novel compounds with appropriate chemical features that can be taken forward as lead series. Here, we describe three prospective case studies, Bruton Tyrosine Kinase (BTK), RAR-Related Orphan Receptor γ t (RORγt), and Human Leukocyte Antigen DR isotype (HLA-DR) to illustrate the positive impact of high throughput virtual screening (HTVS) on the successful identification of novel chemical series. Each case represents a project with a varying degree of difficulty due to the amount of structural and ligand information available internally or in the public domain to utilize in the virtual screens.

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We have developed a workflow to extract, separate, and semi-quantify bioactive oxysterols from mouse colon tissues and fecal matters using solid- and liquid-phase extractions, enzymatic and chemical modifications, and stable-isotope dilution LC/MS/MS. The method was applied to a dextran sodium sulphate (DSS)-induced mouse colitis model, which revealed that one particular dihydroxycholesterol (diOHC), 7α,25-diOHC, was significantly elevated in both colon tissue and fecal matters of mice with colitis compared to that in naïve mice. The extent of 7α,25-diOHC elevation was positively correlated with colitis severity.

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Here, we report a high-throughput virtual screening (HTVS) study using phosphoinositide 3-kinase (both PI3Kγ and PI3Kδ). Our initial HTVS results of the Janssen corporate database identified small focused libraries with hit rates at 50% inhibition showing a 50-fold increase over those from a HTS (high-throughput screen). Further, applying constraints based on "chemically intuitive" hydrogen bonds and/or positional requirements resulted in a substantial improvement in the hit rates (versus no constraints) and reduced docking time.

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We report a Cu(I)-catalyzed azide-alkyne-allyl halide three-component reaction for a one-pot synthesis of 1,4-disubstituted 5-allyl-1,2,3-triazoles. The allyl moiety provides not only the electrophile but also a coordinating ligand to Cu, which is essential for the reaction to occur under mild conditions. A concise synthesis of a potential drug candidate 1 is realized based on this key reaction.

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The preclinical characterization of novel phenyl(piperazin-1-yl)methanones that are histamine H3 receptor antagonists is described. The compounds described are high affinity histamine H3 antagonists. Optimization of the physical properties of these histamine H3 antagonists led to the discovery of several promising lead compounds, and extensive preclinical profiling aided in the identification of compounds with optimal duration of action for wake promoting activity.

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In this paper we report the development of chromatographic methods for the separation of 8 biologically active hydroxycholesterols (OHC's) which include the single-hydroxyl addition species 7α-OHC, 7β-OHC, 25-OHC and 27- OHC, together with the double-hydroxyl addition species 7α, 25-OHC, 7β, 25-OHC, 7α, 27-OHC, and 7β, 27-OHC. Four complementary techniques were employed (gas chromatography, normal phase and reversed phase high performance liquid chromatography, and supercritical fluid chromatography), and for each of the techniques, an optimized method for the separation of all eight compounds in a mixture is presented.

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CuI/L5 (N,N'-dimethylethylenediamine) proves to be an efficient catalyst system for the amination of arylhalides with guanidines. The same catalyst system is then successfully applied to the one-step synthesis of 1-H-2-amino-benzimidazoles through tandem aminations of 1,2-dihaloarenes in modest yields. This methodology is also applicable for the preparation of 1-H or 1-substutituted 2-aryl- or 2-alkyl-benzimidazoles.

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The synthesis and structure-activity relationships of a series of novel phenoxyphenyl diamine derivatives with affinity for both the histamine H(3) receptor and the serotonin transporter is described.

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A series of novel 4-aryl-1,2,3,4-tetrahydroisoquinoline-based histamine H(3) ligands that also have serotonin reuptake transporter inhibitor activity is described. The synthesis, in vitro biological data, and select pharmacokinetic data for these novel compounds are discussed.

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In supercritical fluid chromatography, the partial phase separation that occurs in the dead volume between automatic backpressure regulator and collection vessels causes significant peak tailing and delayed arrival of compounds to the collectors. As a result, when two peaks are barely baseline separated, it becomes very difficult to correctly set fraction collection triggers, which in turn results in fractions being collected with lower purity and lower yield. The problem can be solved with a simple addition of a four-port, two-position switching valve between UV detector and automatic back pressure regulator.

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An automated, accurate and reliable way of acquiring and processing flow injection data for exact mass measurement using a bench-top electrospray ionization time-of-flight (ESI-TOF) mass spectrometer is described. Using Visual Basic programs, individual scans were selected objectively with restrictions on ion counts per second for both the compound of interest and the mass reference peaks. The selected "good scans" were then subjected to two different data-processing schemes ("combine-then-center" and "center-then-average"), and the results were compared at various ion count limit settings.

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Specific sequences in heparin are responsible for its modulation of the biological activity of proteins. As part of a program to characterize heparin-peptide and heparin-protein binding, we are studying the interaction of chemically discrete heparin-derived oligosaccharides with peptides and proteins. We report here the isolation and characterization, by one- and two-dimensional 1H NMR spectroscopies, of ten hexasaccharides, one pentasaccharide, and one octasaccharide serine that were isolated from depolymerized porcine intestinal mucosal heparin.

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